Pyelonephritis most often occurs as a result of urinary tract infection , particularly when there is occasional or persistent backflow of urine from the bladder into the ureters or an area called the kidney pelvis. See: Vesicoureteric reflux

Pyelonephritis can be sudden (acute) or long-term (chronic).

Acute uncomplicated pyelonephritis is the sudden development of kidney inflammation.

Chronic pyelonephritis is a long-standing infection that does not go away.

Pyelonephritis occurs much less often than a bladder infection, although a history of such an infection increases your risk. You're also at increased risk for a kidney infection if you have any of the following conditions:

Due to the high death rate in the elderly population and the risk of complications, prompt treatment is recommended. Sudden (acute) symptoms usually go away within 48 to 72 hours after appropriate treatment.

Your doctor will select the appropriate antibiotics after a urine culture identifies the bacteria that is causing the infection. In acute cases, you may receive a 10- to 14-day course of antibiotics.

If you have a severe infection or cannot take antibiotics by mouth, you may be given antibiotics through a vein (intravenously) at first.

Chronic pyelonephritis may require long-term antibiotic therapy. It is very important that you finish all the medicine.

Commonly used antibiotics include the following:

Amoxicillin

Cephalosporin

Levofloxacin and ciprofloxacin

Sulfa drugs such as sulfisoxazole/trimethoprim

Support Groups:

Expectations (prognosis):

With treatment, most kidney infections get better without complications. However, the treatment may need to be aggressive or prolonged.

Pregnant women and persons with diabetes or spinal paralysis should have a urine culture after finishing antibiotic therapy to make sure that the bacteria are no longer present in the urine.

In rare cases, permanent kidney damage can result when:

Chronic kidney infections occur in a transplanted kidney

Many kidney infections occur during infancy or childhood

Acute kidney injury (acute renal failure) may occur if a severe infection leads to significantly low blood pressure (shock). The elderly, infants, and persons with a weakened immune system have an increased risk for developing shock and a severe blood infection called sepsis . Often, such patients will be admitted to the hospital for frequent monitoring and IV antibiotics, IV fluids, and other medications as necessary.

Severe episodes of acute kidney injury may result in permanent kidney damage and lead to chronic kidney disease.